1990 6 spd oil
 

WHAT IS THE BEST OIL TO PUT IN THE 6 SPD. I HERE DIFFERT THINGS LIKE 30 WEIGHT HD ENGINE OIL? 19k on car. thanks for any help.

Pennzoil Synchromesh is easily obtainable at your local store but I have to ask is there a reason for the oil change? You only have 19k miles on the car.

Castrol,only seen it at BMW dealers.Check out the ZR1.NET site.

For normal driving several good quality transmission oils will work just fine. For the best I chose Castrol 10 w 60 that can be purchased at any BMW dealer at $9 a qt last time I bought it. Since your trans requires 2.2 qts just top it off with Lucas gear lube for the last 2 tenths. That prevents you from buying a 3rd quart that will sit for years and probably be out dated by the time you need to change it again. I still have oil from the early 2000s that Castrol sold as engine oil and is the same stuff we are using now. The ZF Doc reccommends it... that means it is good enough for me. :thumbs:

:iagree:

Bill Boudreau specializes in the ZF6-40 used in our Vettes. From first hand experience, he is a top notch person to deal with, and his web site has a good deal of information about the care and operation of the trans, as well as the clutch and things to watch for.

All that to say, he recommends the Castrol 10W60, AND he recommends periodic changes as well - contrary to what GM and others say.

Send email to billb@zfdoc.com or call Bill Boudreau at (602) 319-6575.

Agree totally on the Castrol. I tried one of the high-name-brand alternatives a few years back and my tranny ran HOT. I called ZF and they verified that the Castrol 10-60 is absolutely the best for our trannies. I drained and swapped to the Castrol and haven't had any problems since.

:iagree: Bill recommand to change it every 15k. I've also had a talk with Bill regarding this matter and he told me that Redline MTL was also a great product for our ZF6 and they also have the BMW 10W60 grade oil.

:cheers:

15k sounds rediculous even autos dont need it before 50k and that fluid will see a lot more heat and abuse. .
Know Bill knows trans well but seems real overkill to me. THey arent made of paper mache:smash:

If you drive her hard, 15k is the magic number my friend! Just look at the amount of brass particuls that come out of your ZF when you drain it, you'll be amaze. I know I was!

If you don't abuse your ZF, then you may keep it as long as the standard lead-time.

:cheers:

:iagree:, There are plenty of ZF6s with over 100k miles that have never had the tranny oil changed. I'm not saying I would do that but just emphasizing the point of changing at 19k miles being overkill. I bet your fluid still looks new and if you do analysis on it you will find it has plenty of service life left.

This always impresses on me that perhaps I'm using the wrong fluid. I've also only used the BMW/Castrol stuff, but the amount of brass/bronze seems bad. If my motor oil was filled with metal shavings at each change, I wouldn't think "I should change the oil more frequently"...

The problem is that there's enough brass particuls after 15k to accelerate the wear of the ZF syncros. That's why it is better to change at 15k. But I do agree that the oils properties are still probably good for an other 50k

:cheers:

the reason why is i had a seal leak. now fixed and has to be refilled

Start drivin the damn thing!
;):D

Makes sense, if you're in a rush go with the Pennzoil. It carries the same spec as the original GM fluid.

For what it's worth...I've had oil analysis done at 9000 on castrol 10w60 and saw another report done at 8000, the viscosity on both reports was equal to 30w oil and was mentioned by the techs as low for that grade of oil, and they said, "it served you well with a low average of wear metals", and after reading that again, I kind of take it to mean, they think the oil was ready to be retired. I'm not trying to say the oil is bad, cause I still think either castrol or redline are the "ones", I just think the high pressures in the transmission break oil down and thats the way it is. But then if the oil will maintain it's 30w properties, then that's what the transmission was suppose to have originally, so it could be good for the long haul, but I wouldn't be able to sleep at night going past 9000. Ok, I'll stop rambling:crazy:

That's not surprising, I'm pretty sure I read somewhere that Castrol 10w60 shears down to a 30wt pretty quickly.

http://i275.photobucket.com/albums/j...Rebuild120.jpg

period

As you can see it is a Liter, not quart
Yes, you will need a hair more than 2 bottles
The oil is a whole lot cheaper than a Bill rebuild
You do the math